Testing Sonication and Different Transport Media to Enhance Microbial Detection in Hard-to-Heal Venous Leg Ulcers

Abstract

Hard-to-heal wounds are frequently associated with underlying conditions such as diabetes, vascular disease, and biofilm-related infections. Accurate identification of microbial origin is essential, but is often hindered by biofilms. This study evaluated whether sonication of wound dressings, combined with different sample transport methods, improves bacterial detection in venous leg ulcers. In a prospective observational case–control study, six patients with hard-to-heal venous leg ulcers received treatments with medical-grade honey (MGH) (n = 1), ceramic dressings – “Cerdak” (n = 2), or hydroactive dressings (n = 3). Three microbiological samples were collected per patient: (1) conventional wound swab (Levin's technique) in Amies medium; (2) sonicate fluid from used dressings transported in sterile tubes without medium; and (3) sonicate fluid in haemoculture tubes (BACT/ALERT). Total pathogen count and diversity were compared across sampling methods. Patient quality of life (QoL) was assessed using the Wound-QoL instrument. Sonication revealed additional pathogens not detected by conventional swabs. The highest number of pathogens was found in sonicate fluid transported in haemoculture tubes (n = 43), followed by swabs (n = 39) and sterile tube transport (n = 30). Adequate treatment significantly improved patients' QoL during the healing process. Dressing sonication, especially with haemoculture tube transport, enhances microbial identification and may improve diagnosis and management of hard-to-heal wounds.